Drawbench apparatus



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A. SUNDH DRAWBENCH APPARATUS 3 Sheets-Sheet 1 Filed Sept. 22. 1921 awoawo c- I LM 3331 h whom Lug mama? A. SUNDH DRAWBENCH APPARATUS Filed Sept.22, 1921 3 Sheets-Sheet 2 3 373$ 51 V I 36, 3 43M 51 AUGUST SUNDH, orHASTINGS-UPON-HUDSON, NEW YORK, ASSIGNOR T0 SUNDH EN- GINEERING ANDMACHINE COMPANY, OF PHILADELPHIA,

CORPORATION OF PENNSYLVANIA.

P NNSYLVANIA, A

DRAWBENCI-I APPARATUS.

Application filed September 22, 1921. Serial No. Q2-,559.

T 0 all whom it may concern: 1

Be it known that I, AUGUST SUNDH, a citi- Zen of the United States,residing in Hastings-upon-Hudson, in the county 'of est,-

chester and State of New York, have invent-,

ed a new and useful Improvement in Drawbench Apparatus, of which thefollowing is a specification.

My invention relates to improvements 1n drawing apparatus and more.especially to apparatus for drawing tubes through a die or the like, tosuitthe gage and shape of the material to be drawn;

Among the objects of my invention is. to I provide means to cushion thedrawing mechanism against the. tube drawing die, means to permit lostmotion in the drawing mechanism, and power means to close the jaws ofthe tube drawing tongs on the tube.

lVith the above objects in View, the invention consists in the apparatushereinafter described and illustrated in the accompanying drawings, inwhich:

Figure 1 is a fragmentary plan view of a suitable bench with myinvention applied thereto.

Figure 2 is a longitudinal vertical view of a drawing mechanism for adraw bench, embodying the principles of the present invention. 7 I

Figure 3 is a top or plan viewof the same.

Figure l illustrates a top or plan view of a part of the drawingmechanism.

Figure 5 is a longitudinal vertical view showing a section of anotherpart of the drawing mechanism.

Figure ('3 is an end view of the drawing mechanism, illustrating some ofthe novel features of the same.

Figure 7 is a sectional end view of a draw bench embodying Figure 6, ina. simplified form, illustrating its position on the draw of the devicein their operative relation to each other.

Figure 1.1 is a fragmentary perspective view of the toggle joint.

Similar characters of. reference are em ployed in the above describedviews to indi- .cate corresponding parts.

My invention, as heretofore stated, ap-

, plies to improvements in drawing apparatus n general, butmoreespecially to apparatus for manufacturing tubing, andas it can be aswell illustrated in connection, with the latter, I will so describe it.

Referrin to Figure 1,therein is illustrat ed, as suita Is formy'purpose, a fragmentary View of a draw bench, 1 comprising a structurebuilt up of longitudinal frame ba rs,2 and 3, to form a track and guidefor the travelling draw mechanism, 4. The bars, 2 and 3, being securedat their front ends to one Side of an abutment, 5, and their rear endsto standards, 6 and 7 the latter being fastened to a bed plate, 8, whichsupports a drum, 9, and' a motor, 10. Secured to the other side of theabutment,-5, is a tank, 11, to contain a liquid into which the tubes aredipped before being drawn. Recessed into the abutment, 5, is a die, 12,held in a vertical position, through which a tube, 13, is

, adapted to'be drawn over. a mandrel. 14,

Closing of the button operates the toggle joint, by meansofcurrentobtained from a source of supply through the wires, 20 and 21.Various mechanism may be employed to propel the drawing mechanism uponthe tracks of the draw bench, 1. For illustrating my invention, Ipreferto use cables or other flexible connections, 22 and 23. Thecables, which are the d 'a-wing or pulling means are secured atone oftheir ends to the draw mechanism, 4, at 24, their other ends beingsecured to the drum, 9. upon which they are wound. The cables, 23, whichare th returning means, that is the means for see Figure 2.

returning the draw mechanism to the die after the completion of thedraw, are also secured to the draw mcchanism'at one of their ends at 25;for illustration of same, The cables then continue throughgrooves, 26,Figure 8, in the inner sides of the longitudinal frame bars, 2 and 3,over pulleys, 27, not seen in Figure 1, as thcy are shown incased incovers, 28, a part of one of the said pulleys however being seen inFigure 8, a part of which pulley extends from within the cover,underneath the tank,

convenientmechanism, as for instance, from the electric motor, 10,through gearing, 29.

Means for operating, and power for the.

motor. 10, being bad by the switch, A, and

from the plus and minus mains.

Referring to'Figures 2 and 3, therein are shown assembly views of thedrawing mech-"Q anism, 4. which comprises supports,,30, 31 andtheir-ends adapted to have sliding contact on the frame bars, 2 and 3,ofthe draw bench, 1. The support, 32, is a crosspiece,

and like the other supports, it-bridges the frame bars. 2 and 3, and hasslidingcontact" thereon. The support, 30, carries theft'o-ngs,

I 17. they being centrally pinned to the supa slot, -10. in the rod.

port by a pin, 33, and adapted to rest on-"a boss, 34, on the support.and which-boss is:

shown in Figure 4. To the tongs pinned connection, 35, by means of pins,36, the

other ends of the connections being pinned by a pin, 37, to a link. 38,in the support, 31. A rod, 39, see Figure l, is fastened to thesupport,30. by the pin, 33; it extends underneath the tongs and isengaged at its other end by the pin. 37, of the link, 38, engaging Thepurpose of the rod will be explained later. The link. 38, is held in thesupport. 31. by means of a slot. 41, see Figure 5, formed for itsreception. There is also a crosspiece. -12. fastened to the link to holdthe link in its slot in the .support. 31. The support. 31. also supportsat its end opposite to the end which holds the link. a draw rod, 43,which draw rod is encompassed by a spring, 44. The support. 31. is coredout as seen in the Figure 5 for the reception of the draw rod, 4.3, anda nut, 4-5. fastened to the end of the draw r'od. cored hole, to, in thesupport. -31. through the part of the slot, 41. in the support. 31,indicated by 47, after which it is scrcwcd to the pin, through anopening, 48, above the The supports, 30 and 31, have tween them.

The nut. in. is placed in the cored hole by a tool, engaging the holesin the nut. The support, ,32, supports the other end of the draw rod,43, together with other parts not spoken of heretofore of the drawingmechanism, and which are a crosspiece, 49, and an equalizing cable hitchbar,

50. The crosspiece is connected to the support, 32, through theintermediat'ion of connections, 51, which are fastened at one ofequalizing cable hitch bar, 50, is fastened the ends, 25. of the cables,23, the cable hitch bar being placed in-the fork, 52, of the draw rod,43, and held therein by a'bolt, 53, which .bolt also is the fasteningmeans of the draw rod, 43, to the support, 32.

5-1 indicates a spacer or bushing between the draw rod, 43, and support,32. Also placed in the fork of the draw rod, 43, and held thereto by apin,

55, is an equalizing cable hitch. 56, and to whichis fastened by pins.57, cable cups, 58, in which are fastened the ends, 24, of the cables,22.

' Beferring particularly to Figures 9, 10

and 11, therein are shown views of the toggle join t,,16, for operatingthe tongs of the drawinginechanism, consisting of bell crank levers, 59and 60. Arms, 61 and 62, of the levers/are somewhat T-shaped. theirpivotal points, 63 and 64, respectively,being loosely journalled to thebench side of the abutment, 5, shown in Figure 9.

To the uppermost end of each arm, (31 and 62, are loosely journalledbars, and 66. respectively. adapted to be moved toward each other,closing the tongs. 17. of the drawing mechanism when the same are be-The hatched squares. 67 and 68, in Figure 10 either side of the bars 65and 66 represent a guide for the bars, which in the case of the drawbench shown in Figure 1, are in the form of slots cutin the abutment, 5,as shown in Figure 9. The other arms, 69 and 70. of the lcvers arelooselypivoted at one of their ends to the lower ends of the T-shapedarms. (31 and 62. of the lever at T1 and 72. respectively. their otherends being pivoted together at Tflto an end of a link. 74. the other endof the link being pivoted between rods. and T6. of a lever, 77, which ispivoted at one of its ends to a bracket, 78, secured to a leg on theopposite side of the bench, opposite the leg. 79. shown in Figure 9.

Between and secured thereto, to the other ends'ot' the rods, 75 and T6.of thc lcvcr, T7. is a bar, 80, which is also loosely jouruallcd in thefork of a bar, 81, the said bar being secured between the fork formed inthe plunger, 82, of an electro-magnet, 83. The coil, 84, and frame, 85,for the coil of the electro-magnet is mounted upon a. base, 86,supported by a bracket, 87, .afiixed to the leg, 79, as illustrated inliigures 8 and 9. An angle iron, 88, secured to the abutment, 5, and tothe frame, 85, of the magnet, is used also as a support therefor. Theaction of the toggle insures that the} tongs will securely grip the tubeto the end that the tongs will not slip on the tube in the beginning ofthe operation of drawing a tube.

T he operation of the draw mechanism and toggle joint will be clearlyevident from the above description, and from an inspection of theaccompanying drawings.

The operation of the abovementioned devices is bllBfl as follows: Thetube to be drawn over a mandrel and through a die is caused to assumethe position indicated in Figure 1., of the drawings the pointed or endportion, 18, of the tube, projecting through the die, 12, into theopened tongs of the drawing mechanlsm, which 1S caused to assume thisopen POSltlOll. The button, 19,

' in Figure 1. is pressed, completing a circuit from the plus main wire,20, through the coil, 8i, of the electro-magnet of 'the toggle joint,button 19, wire 20, to the minus main. The coil is then energized,drawing its plunger, 82, into itself, the toggle fjoint assuming aposition as in l igurelththe bars, and 66, of the toggle joint, willhave moved the tongs of the drawing mechanism to cause it to be closedupon the end portion of the tube to be drawn, after which the button,19, is released. and the bars. allowed to be come free of the grip. Thedrawing mechanism is then started to travel by means of the motor, 10,causing the drawing mecha nism to be pulled along the track formed bythe frame bars. 2 ,and3, towards the rear end of the draw bench. drawingthe tube, 13, over a mandrel. ll. andthrough the die, 12. It can readilybe seen;that,=ias a result of the initial grip of the tongsnpon the endof the tube. by the action of the toggle, and by the design of theclamping tongs. the harder the pull required todraw the tube, thegreater will be the gripping actiouof the tongs upon the tube.The-initial grip of the tongs upon the tube. caused by the toggle joint.insures a positive grip upon the tube in the beginning of the drawingoperation. 4 I

Upon completion of the 'draw the tongs releases its hold upon the tube.as there is no resistance to ovcrcmne. namely the resistance ot the die.as the tube has been cntirely pulled through it, the tube falling out ofthe tongs ol the grip due to its own weight. and in the case of the drawbench in mind, the tube fall into a container lorated underneath thebench, thus eliminatmg any manual means for removing the tube from thebench. The drawing mechanism is then caused to travel back to the frontend of the bench through a reversal of the motor, 10. by means ofswitch, A. At the start of the return operation, the tongs automaticallyopen,'the resistance offered by the joint connection formed by theconnections, 35, between the gripand the support, 31, being less thanthe resistance to be overcome in causing the support, 30, which carriesthe tongs to be moved. Accordingly the pin, 37, in the link, 38, in thesupport, 31, will travel in the slot. 4:0, n the rod, 39, underneath thetongs, until it assumes aposition as shown in the Fig ure 4, which showsa cross-section of the pin. The support, 30, will then be caused totravel with its opened tongs, being-virtually pushed by the othersupports. 31- and 32, behind it. As will be seen from the aforegoingexplanation the tongs are al ways open in the return operation,consequently, being in that position at arriving at the front end of thebench to, be in a position to engage another tube to be drawn as before.V

Should the operator fail to stop the drawing mechanism in time or shouldthe automatic means used on some draw benches fail to render the powermechanism,inoperative, the drawing mechanism,-l, will abut against thedie, 12, with undue shock to the bench, and in the instance wherecables. or other flexible means are used as a return means. the saidmeans may be broken as a consequence. This however is eliminated by thebuffer effect embodied in the drawing mechanism, whereas when thedrawing mechanism abuts against the die the support, 32, to which thereturn cables, 23, are fastened, will still be allowed to move throughthe movement imparted to the draw rod, 43, affixed to it. the draw rodand nut. 45, affixed to it, being projected into the hole. -16. in thesupport, 31. compressing the spring -l-l. The tongs, 17. ot the drawingmechanism, 4., are always in an open position when returned to the die,12. for reasons before stated. and that when the drawing mechanism abutsagainst the die, that the motion of all its parts are not stopped, bythe effect,

but that through the further motion of other 7 parts, by the drivingmotor, 10, through the intermediation of return cables, 23, the drawrod, 43. and nut, 45. are projected against the spring, 44. into thehole. 4-6. of the member. 31, until the driving motor, 10, is stopped,all of which has been stated before. As a consequence the motor foroperating the draw bcnch mechanism will be allowed to start under noload. before it commences actually to draw a tube. the motor. 10, instarting pulling the draw rod, 43, and nut,

. could be inc 45, from its projected position through theintermediationof the pulling cables, 22, at

the end of which it will commence actually to draw the tube. The ,abovedescribed loose connection between the pulling cables 22 and drawingtongs, broatlly stated, at the beginning of the movement of the cablesin the operation .ot pulling the tongs to draw a tube, may bercferred toas a lost motion de- "ased, lengthening the cor hole,ff,.-t(l, t hestroke of, the draw rod, 43, would tlinb'egreater, the length of thedraw rod, and also. the spring, 44, to be increased if necessary.

I'Iavingthus described my iiwention, I

. claim as new. and desire to secure byLetters Patent ofth'ellnitedStates:

1. 'In"anapparatus for drawing metal tubes having a stationary tubedrawing die and 'traveling tube drawing mechanism, adapted to travelfrom and to the die, a spring adapted to cushion the.v drawing mechanismagainstthe die in its return travel thereto.

In ail apparatus for drawing metal tubes having a stationary tubedrawingdie and traveling tube drawing mechanism, adapted to travel fromand return to the die.a rod in said drawing mechanism and a spring onsaid rod to cushion the drawing mechanism against. the die upon itsreturn thereto.

3, In a drawing mechanism for drawing ,metaltubes. the combination of astationary tube drawing die, tongs to grip the tube to draw it. throughthe die. actuating means to move the. tongs to draw the tube through thedie and a lost motion device between the tongs and actuating means.

l. An apparatus for drawing metal tubes consisting of the combination ofa stationary tube drawing die, a pair of traveling tongs tor drawing thetube through the die adapted to travel from the die in drawing a tube,an electric motor for moving the tongs from the die to draw a tube, andconnections including a lost motion device between the motor and tongs,whereby the motor can be started from rest to be brought up to a desiredspeed before it moves the tongs to draw atube.

5. In an apparatus for drawing metal tubes, the combination of astationary tube drawing die, a pair of traveling tongs to grip the tubeto be drawn and travel from the die in drawing a tube through it, a.

traveling support for the tongs and to which they are fastened, a drawrod, one end adapted to engage the support and be partially drawnthrough it, means fastened to the other end of the rod for moving it,whereby the rod is allowed to move a distance in said support before itbegins to move the support and the tongs to draw the die. 7

6. In an apparatus for drawing metal tubes, the combination ofastationary tube drawing die, a pair of traveling tongs adapted to gripthe tube to be drawn through the die and travel from the die in drawingthe the tube through tube through it, a traveling support for the tongsand to which they are fastened, a draw rod, one. end sleeved into andadapted to be partially drawn through and engage the support, meansfastened to the other end of the rod for moving it and a coiled springon the rod for cushioning the tongs against the die in their returntravel to the die.

7. In an apparatus for drawing metal tubes, the combination of a pair oftongs for gripping the tube to be drawn, bell crank levers to close thetongs, a toggle joint device between the bell crank levers, anotherlever conn'ectedfto the toggle joint device, and electric means toactuate said last mentioned lever to actuate the toggle joint device andthe bell crank levers to close the tongs on the tube.

In testimony whereof, name to this specification.

AUGUST SUNDH.

I have signed my

